Abstract: A zone valve hot water recirculation system in accordance with the present invention generally includes a hot water source, such as an electric or gas water heater, a conduit for enabling circulation of hot water from hot water source to one or more plumbing fixtures and recovery of water to the hot water source, a pump for accelerating delivery of hot water to the fixtures and, importantly, a zone valve for preventing flow of water into the hot water source during standby periods of the hot water source. A controller, which may include an electronic timer, is provided for causing the zone valve to open and close and the pump to start and stop.

Abstract: Plumbing apparatus is provided for reducing energy consumption of a hot water heater, the apparatus includes a tank and a buoyant piston movably disposed within the tank and having a perimeter slidably engaging an inside wall of the tank. Water entering a top of the tank pushes the buoyant piston towards a bottom of the tank and at a selected position, grooves are provide in an inside wall of the tank to enable entering water to pass the buoyant piston. When the apparatus is connected between a conventional hot water heater and a cold water source, the water heater is buffered from the cold water source for small draws of water from the hot water heater thus preventing such small draws of water from tripping the water heater thermostat.

Abstract: Plumbing apparatus is provided for reducing energy consumption and controlling increases in water pressure of a hot water heater. The apparatus includes a tank and a buoyant piston movably disposed within the tank and having a perimeter slidably engaging an inside wall of the tank. Water entering a top of the tank pushes the buoyant piston towards a bottom of the tank and at a selected position, grooves are provide in an inside wall of the tank to enable entering water to pass the buoyant piston. When the apparatus is connected between a conventional hot water heater and a cold water source, the water heater is buffered from the cold water source for small draws of water from the hot water heater thus preventing such small draws of water from tripping the water heater thermostat. The buoyant piston is designed to enable expansion of tank capacity such that upon increases in water volume due to thermal expansion, pressure within the tank is controlled and rupture of the tank is prevented.

Abstract: A hot water appliance is provided with an accelerated delivery system which includes a pump interconnected between hot and cold water fittings and a control system for causing the pump to circulate water from the hot water fitting into the cold water fitting when the hot water appliance is turned on. Temperature sensor is provided for causing the control system to stop the pump to prevent heated water from being circulated into the cold water fitting. In addition, a hot water demand system may incorporate a sound sensor detecting water flow in a hot water delivery line and a sound-generating element may be provided for providing a characteristic sound in response to water flow in the hot water delivery line.